Airplane



L. J. TETLOW Aug. 29, 1933.

AIRPLANE Filed Aug. 19, 1929 4 Sheets-Sheet l iii! L. J. TETLOW Aug. 29, 1933.

AIRPLANE Filed Aug. 19, 1929 4 Sheets-Sheet 2 LEW 5 J TE r00;

' Aug. 29, 1933.

L.- J. TETLOW AIRPLANE Filed Aug. 19, 1929 4 Sheets-Sheet 3 L. J. TETLOW Aug. 29, 1933.

AIRPLANE Filed Aug. 19, 1929 4 Sheets-Sheet 4 Patented Aug. 29, 1933 UNITED: STATES PATENT OFFICE 1,924,471 AIRPLANE Lewis J; Tetlow, Holyoke, Mass. Applicatien August 19, 1929. Serial No. 386,925 14 Claims. (01. 244, 29)

This invention relates to airplanes and has for one of its principal objects theprovision of a braking device for checking the speedofthe plane in landing, the device automatically adjusting itself when manually operated to effect a gradual application of the to render the manual operation easy.

Another object is to provide a wing construction which is strong and light, the parts of which are adapted to be manufactured at low cost and to be readily assembled, and which can be readily mounted on or dismounted from the fuselage. Another object is to provide a support for the lateral motors, which is very strong and simple fuselage entirely independently of the planes.

Another object is to provide on the landing gear a cushion support of novel and eflicient design for the fuselage.

Still another object is to provide a tail skid which is adapted to yield both vertically, to abof an airplane a somewhat larg'er 4-4 of Figure 2;

Figure 5 is a detail section on line 5-5 of Figure 2; 1

Figure 6 is a plan view of one of the wings with the fabric covering removed;

Figure 7 is a transverse section on line 7-7 of Figure 1; 1

. Figure 8 is adetail section illustrating a tail skid embodying my invention; and l 1 Figure 9 is a sectional detail on line 9-9 of Figure 7.

While the machine illustrated is of the monoplane type, it is to be understood that features of my invention are adapted to machines of other types. The numeral 10 designates the fuselage, which is a hollowbody of cylindrical sections. 11 designates the elevating planes, 12 the rudder, and 13 and 14, the horizontal and vertical stabilizers, respectively. The parts may be constructed in any suitable manner, in so far as my invention is concerned.

braking forces and in construction and which is supported by the Figure 4 is a transverse sectional view on line,

One of thefeatures of my invention resides in the construction and mounting of the wings 15.

Referring particularly to Figures 6 and 7. it will be observed that the framework, or skeleton, of the wing is made up of end castings 16 and longitudinal ribs 17, the latter consisting of vertically disposed flat bars, preferably of steel or some stronger material, bolted at their ends to inwardly extending lugs 18' on the end castings. Cross ribs are formed by' stampings 18, 19 and 20, of 55 aluminum or other satisfactory metal formed 'with triangular openings to givethem a girder on truss formation and to make them as light aspo= sible, the upper and. lower edges of these stampings being curved to form the desired camber. As clearly shown in Figure 6, the stampings are arranged in pairs, back to back. The intermediate stampings 19 are flanged at both ends and bolted through the longitudinal ribs'17' to corresponding flanges formed on the inner ends of stampings .18,

and 20. The free edges of the pairs of stampings 18 and 20 are secured together in any suitable manner, for example, by rivets. f

Secured over the curved edges of stampings 18 and casting 16 is a thin metal plate 21, preferably of aluminum, and a similar plate 22 is mounted over the edges of stampings 20. The wing frame further includes horizontally disposed plates 22' of steel or other suitable metal which are screwed or otherwise fastened to lugs 23 extending from 35 the loweredges of stampings 19. The wing skeleton thus constructed is covered bya suitable fabric in usual manner. By forming the longitudinal ribs of the frame of bars and the cross ribs of stampings flanged and bolted to the bars, I produce a frame having great strength combined with lightness. The elements can be easily manufactured at low cost and can be readily assembled to form the complete frame;

The wings are secured to the fuselage in the manner indicated in Figures 3 and 4. Bolted to the top of the fuselage 10 is a seat 24, the bolts being designated by the numeral 25., The inner castings 16 of the wing skeleton are formed with ears 26 which are secured to the seat 24 by bolts 27. Detachably secured in any suitable manner over the ears and bolts is a metal cover 28. The wings are braced by diagonally extending tie rods 29, which are secured at their upper ends by bolts 30 passing throughapertures 31 in a central bar 22' of the" wing'frame (see Figure 6) and are adjustably secured at their lower ends to piston rods 32 of dash pots 33. By adjusting the positions of the lower ends ofrods 29 'on the piston rods 32, the dihedral angle formed by the wings can be varied as much as 10 degrees, the resiliency of the manner of supporting and mounting the wings facilitates assembly and renders it easy to disassemble the Wings for repairs or replacement,

particularly since they are quite, independent of the motors.

As shown, the airplane is equipped with five motors, a front central motor 35 and two smaller motors 36 at each side of the center line and disposed at the front and rear, respectively; of the planes. A feature of my invention resides in the mounting of the lateral motors 36 on the fuselage. Referring particularly to Figures 3, 4 and 5, it will be observed that these motors are supported on transverse horizontal beams 37, formed preferably of an alloy stronger than steel, which beams extend through the cylindrical, body of the fuselage 10 on a chord slightly below the horizontal diametrical plane of said body. These beams are fastened by bolts 38 to horizontal lateral flanges 39 projecting from the body 10 and the beams have their outer ends formed integrally with saddles 40 in which the motors are mounted. Bolted to the under sides of beams 37, adjacent the fuselage 10 and on each side thereof, are laterally diverging and longitudinally converging members, or legs, 41, which integrally meet at an angle and are formed with vertical slots 42 through which pass the axles 43 of the landing wheels 44. The motor carrying beams 37 are reinforced by diagonal struts 45 bolted at their upper ends to the beams and at their lower ends to the lugs 41.

The dash pots 33, previously referred to, are supported on a saddle 46 having depending forked extremities in which the axles 43 are secured and through which the convergent ends of legs 41 extend. The upper ends of piston rods 32 of the dash pots are seated loosely in vertical sockets formed in members 47, which are bolted to the undersides of bars 48, the latter being secured at their ends to the flanges 39. The fuselage is thus supported on the landing gear, including saddle 46, through the piston rods 32 and the dash pots 33. 7

Normally the pistons in the dash pots are raise by the springs inthe dash'pot cylinders holding the fuselage at its maximum distance from saddle'46, as shown in Figure 4, the bottoms of the slots42 in legs 41- engaging the axles 43 of the landing wheels. On landing, of course, the fuselage and attached parts move towards the saddle 46 against the action of the dash pots, and slots 42 permitting the legs 41 to move relatively to the axles 43. This construction provides a simple and rugged cushioning device which very effectively absorbs the shocks due to landing, and is advantageous over the long helical springs heretofore commonly used for this purpose, both in efficiency of action and in construction.

Perhaps the principal feature of my invention resides in improved mechanism for retarding the, movement, or brakingqthe airplane in landing. Figures '7 and 9 show my improved braking mechanism in detail. Mounted above the planes adjacent each of the outer ends thereof is a small auxiliary plane 50. This auxiliary wing is resiliently mounted on two rods 51 which are fastened at their lower ends in a pair of the ears 23 which project from the lower edges of stampings 19 and which pass through ears 52 projecting from the upper edges of said stampings and wooden filler blocks 53. These two rods pass through vertically aligned enlarged apertures 54 in the wing 50 and have nuts 56 on their upper ends bearing against the upper surface of the wing, the latter being normally held against the nuts by means of stiff coil springs 56 which surround barrels 5'7 on the rods and hear at their lower ends against flanges projecting from the bottom of the barrels, the upper end of each barrel being open and spaced from the under side of the aileron. Projecting laterally from both sides of the auxiliary wing near the trailing end thereof is a pin, or bolt, 53, which passes through a curved slot 59 formed in the upper end of a bracket 60, the latter having a foot which is secured on top of the plane 15 by screws 61 which are tapped through holes 62 in flanges 63- projecting horizontally from the upper edges of stampings 19 (see Figures-6 and 7), Set screws 64 are adapted to engage pins 58 to limit the upward movement of the trailing end of the auxiliary wing. The brackets 60 have rearwardly extending arms 65 in which the endsof a horizontal rod 66 are pivoted, and secured in a longitudinal slot of this rod is a vane or aileron 67. This vane is adapted to be held horizontally or placed at any desired angle to the line of movement of the plane by suitable connections (not pocket substantially closed at the rear, and the resistance to the flow of air offered by these pockets effectually checks the speed of the plane and brings the latter quickly to a stop. In coming to the positions indicated in Figure 7, it will be noted that the vanes operate to deflect the air currents downwardly from the under sides of the trailing ends of the auxiliary wings, thus creating a partial vacuum at these points. The pressure differential thereby produced causes a depression of the trailing portions of the wings against the tension of springs 56, this downward movement being limited by engagement of the pins 58 with the bottom of slots 59 and by engagement of the underside of the auxiliary wing with the top edges of barrels 57. When the vanes 67, however, approach their full'braking positions, in which the escape of air between their free edges and the top sides of the plane 15 is very much restricted, the banking up of the air against the ailerons destroys the partial vacuum under the trailing ends of the auxiliary wings and indeeed produces an air pressure which causes the wings to resume their normal posi- 145 tions. Thus it will be noted that it is only during the movement of the vanes toward braking positions that the auxiliary wings are depressed at their trailing ends. After the ailerons have been brought substantially to their braking posltions, the auxiliary wings move backto their normal positions indicated in Figure 7.

I have demonstrated in' the practical use of a machine embodying this feature of my invention that these movements of the auxiliarywings produces a graduation in the braking effects and renders it easy for the operator to move the ailerons downwardly into full braking position,

By causing the wings to move. downwardly at their trailing ends automatically in correspondence with the movements of the vanes i. e., by having the auxiliary wings flexible it is clear that the vanes are shielded from the full effects of the air currents and a more gradual braking application is thereby attained than would be the case were the smaller wings rigidly mounted. It should be particularly noted, however, that when the vanes approach full braking position, the auxiliary wings move back to their normal positions and full braking effects are then produced. While the same effect could be had by making the trailing end of the wing yieldable I much prefer to have the wing rigid per se and be flexibly mounted.

A still further feature of my invention resides in the construction of the tail skid shown in Figure 8. It will be observed that the skid is of resilient construction, being formed of a plurality of leaf springs '70. These leaf springs the tension of which may be adjusted by moving the lower transverse holding strap 69 are bolted to a plate '71 secured to the lower end of a cylindrical mentber 72 which is housed in a barrel '73 depending from the rear end of the fuselage 10. Member 72 is adapted to rotate on a vertical axis through a limited angle, but is normally held resiliently so as to dispose the skid in a fore and aft line. For this purpose member l2 is surrounded by a coil spring 74 which has its lower end secured to member '72 and its upper end secured to barrel. '73. A stop screw 74 is tapped through barrel 73 and has its inner end engaged in a slot formed. rear the upper end of member '72. Spring 74 resiliently holds the skid in a fore and aft position but permits the skid to rotate on either side of this position through an angle determined by the stop screw 75. Thus the skid by its spring construction and spring mounting is movable vertically as well as horizontally, so that it will absorb the vertically directed shocks incident to landing and will automatically turn on a vertical axis in correspondence with the turning movements of the plane after landing.

Many and various changes in the specific constructions shown and described herein will naturally occur to mechanics skilled in this art. The invention therefore is not intended to be limited by the specific descriptions, but the scope of the invention will appear from the appended claims.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:-

1. In an airplane, braking mechanism comprising in combination, an auxiliary wing mounted above the plane adjacent each end thereof," and adapted to yield vertically at its trailing end and a vane pivoted adjacent the trailing edge of the flexible wing adapted to form a pocket with the latter and with the upper surface of the plane.

2. Inan airplane, braking mechanism comprising, in combination, a wing flexibly mounted above the plane, said wing being movably mounted so that its trailing portion can move downwardly through a limited path; 'an aileron pivoted on a relatively stationary axis parallel and adjacent to the trailing edge of said wing and adapted to be moved downwardly to a position where its free edgeis slightly above the upper surface of the plane.

3. In an airplane, braking mechanism, comprising in combination, .rods secured to the plane and projecting above the same, a wing having en-' larged apertures adjacent its central portion through which said rods extend, stops on the upper ends of the rods limiting the upward movement of the wing, coiled springs surrounding the rods and bearing against the underside of the wing and normally holding the wing against said stops, a pair of brackets secured to the plane adjacent the trailing portion of the wing and provided with slots, pins projecting from the trailing end of the wing and engaging said slots,

and a vane pivoted in said brackets adjacent the trailing edge of the wing and adapted to have its free edge brought into proximity to the upper surface of the plane.

4. In an airplane, braking mechanism comprising in combination, auxiliary wings mounted on the plane adjacent each end thereof, and adapted to yield vertically at their trailing ends and vanes pivoted adjacent the trailing edges of the auxiliary wings adapted to form pockets. with the latter and the surface of the plane;

5. In an airplane, braking mechanism comprising in combination, means mounted on the plane and adapted to yield vertically at its trailing end and means pivoted adjacent the trailing edge of said first mentioned means adapted to form, a pocket with the latter and with the surface of the plane.

6. In a airplane, braking mechanism comprising in combination, auxiliary means flexibly mounted on the plane adjacent each end thereof and adapted to yield vertically at its trailing end and means pivoted adjacent the trailing edge of said auxiliary means adapted to form a pocket with the latter and with the surface of the plane. 7. In an airplane having a main wing, braking mechanism comprising in combination, an auxiliary wing member mounted on the main wing, and adapted to yield vertically at its trailing edge, I and means on the main wing adapted to limit the vertical movement of said auxiliary member, and a vane carried by said limiting means, said vane being pivoted to turn about a horizontal axis adjacent to but fixed with respect to said yielding edge.

8. In an airplane, braking mechanism comprising in combination, auxiliary means mounted on the plane, and adapted to yield vertically at its trailing end, means on the plane adapted to limit the vertical movement of said auxiliary means, and a vane pivoted to said limiting means adapted to form a pocket with said auxiliary means and 'with the surface of the plane.

9. A brake for airplanes comprising auxiliary means mounted on the plane and adapted to yield vertically at its trailing edge, means connected to the trailing edge of the auxiliary means and the plane to limit the movement of said auxiliary means, said limiting means including a pivoted vane adapted to be turned toward the surface to have its free edge brought into proximity to thesurface of the plane.

, 11. In an airplane including auxiliary braking mechanism, brackets secured to the plane and provided with means adapted to limit vertical movement of the auxiliary braking mechanism, said brackets being provided with slots, pins projecting from the trailing portion of the auxiliary braking mechanism and engaging said slots and adjustable means engaging said pins for limiting the movement of the pins.

12. In an airplane, safety mechanism comprising in combination, an auxiliary Wing mounted on one of the planes and adapted to yield vertically at its trailing edge and a vane pivoted adjacent said trailing edge adapted to form a pocket with the Wing and the surface of the plane.

13. In an airplane, an auxiliary wing mounted to turnabout a longitudinal axis, an aileron pivoted to turn about an axis spaced from said first axis and adjacent one edge of said wing, said wing being movable independent of said aileron.

14. In an airplane, an auxiliary wing pivotally mounted on the plane, an aileron pivoted adjacent one edge of said wing on an axis spaced from the pivotal axis of said wing, said wing being movable independent of said aileron.

LEWIS J. TETLOW. 

